/*
 * @BEGIN LICENSE
 *
 * Psi4: an open-source quantum chemistry software package
 *
 * Copyright (c) 2007-2024 The Psi4 Developers.
 *
 * The copyrights for code used from other parties are included in
 * the corresponding files.
 *
 * This file is part of Psi4.
 *
 * Psi4 is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * Psi4 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with Psi4; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * @END LICENSE
 */

/*! \file
    \ingroup CCDENSITY
    \brief Enter brief description of file here
*/
#include "psi4/libdpd/dpd.h"
#include "MOInfo.h"
#include "Params.h"
#include "Frozen.h"
#define EXTERN
#include "globals.h"

namespace psi {
namespace ccdensity {

/* BUILD_A_UHF(): Construct the components of the molecular orbital
** Hessian, A, for UHF orbitals. At the moment we're actually building
** all symmetry blocks of A, though for the orbital Z-vector equations
** we really only need the totally symmetric components.
**
** A(AI,JB) = delta_IJ f_AB - delta_AB f_IJ + <IJ||AB> - <JA||IB>
**
** A(ai,jb) = delta_ij f_ab - delta_ab f_ij + <ij||ab> - <ja||ib>
**
** A(AI,jb) = 2<Ij|Ab>
**
** TDC, January 2003
*/

void build_A_UHF() {
    int h, nirreps, row, col;
    int a, i, b, j;
    int A, I, B, J;
    int Asym, Isym, Bsym, Jsym;
    dpdfile2 fIJ, fij, fAB, fab, fIA, fia;
    dpdbuf4 Amat, D, C;

    nirreps = moinfo.nirreps;

    global_dpd_->file2_init(&fIJ, PSIF_CC_OEI, 0, 0, 0, "fIJ");
    global_dpd_->file2_mat_init(&fIJ);
    global_dpd_->file2_mat_rd(&fIJ);
    global_dpd_->file2_init(&fij, PSIF_CC_OEI, 0, 2, 2, "fij");
    global_dpd_->file2_mat_init(&fij);
    global_dpd_->file2_mat_rd(&fij);
    global_dpd_->file2_init(&fAB, PSIF_CC_OEI, 0, 1, 1, "fAB");
    global_dpd_->file2_mat_init(&fAB);
    global_dpd_->file2_mat_rd(&fAB);
    global_dpd_->file2_init(&fab, PSIF_CC_OEI, 0, 3, 3, "fab");
    global_dpd_->file2_mat_init(&fab);
    global_dpd_->file2_mat_rd(&fab);
    global_dpd_->file2_init(&fIA, PSIF_CC_OEI, 0, 0, 1, "fIA");
    global_dpd_->file2_mat_init(&fIA);
    global_dpd_->file2_mat_rd(&fIA);
    global_dpd_->file2_init(&fia, PSIF_CC_OEI, 0, 2, 3, "fia");
    global_dpd_->file2_mat_init(&fia);
    global_dpd_->file2_mat_rd(&fia);

    global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 0, 5, 0, 5, 1, "D <IJ|AB>");
    global_dpd_->buf4_sort(&D, PSIF_CC_MISC, rpsq, 21, 21, "A(AI,BJ)");
    global_dpd_->buf4_close(&D);
    global_dpd_->buf4_init(&D, PSIF_CC_CINTS, 0, 20, 20, 20, 20, 0, "C <IA||JB>");
    global_dpd_->buf4_sort_axpy(&D, PSIF_CC_MISC, qrsp, 21, 21, "A(AI,BJ)", -1.0);
    global_dpd_->buf4_close(&D);

    global_dpd_->buf4_init(&Amat, PSIF_CC_MISC, 0, 21, 21, 21, 21, 0, "A(AI,BJ)");
    for (h = 0; h < nirreps; h++) {
        global_dpd_->buf4_mat_irrep_init(&Amat, h);
        global_dpd_->buf4_mat_irrep_rd(&Amat, h);

        for (row = 0; row < Amat.params->rowtot[h]; row++) {
            a = Amat.params->roworb[h][row][0];
            i = Amat.params->roworb[h][row][1];
            A = fAB.params->rowidx[a];
            I = fIJ.params->rowidx[i];
            Asym = fAB.params->psym[a];
            Isym = fIJ.params->psym[i];
            for (col = 0; col < Amat.params->coltot[h]; col++) {
                b = Amat.params->colorb[h][col][0];
                j = Amat.params->colorb[h][col][1];
                B = fAB.params->colidx[b];
                J = fIJ.params->colidx[j];
                Bsym = fAB.params->qsym[b];
                Jsym = fIJ.params->qsym[j];

                if ((I == J) && (Asym == Bsym)) Amat.matrix[h][row][col] += fAB.matrix[Asym][A][B];
                if ((A == B) && (Isym == Jsym)) Amat.matrix[h][row][col] -= fIJ.matrix[Isym][I][J];
            }
        }

        global_dpd_->buf4_mat_irrep_wrt(&Amat, h);
        global_dpd_->buf4_mat_irrep_close(&Amat, h);
    }
    global_dpd_->buf4_close(&Amat);

    global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 10, 15, 10, 15, 1, "D <ij|ab>");
    global_dpd_->buf4_sort(&D, PSIF_CC_MISC, rpsq, 31, 31, "A(ai,bj)");
    global_dpd_->buf4_close(&D);
    global_dpd_->buf4_init(&D, PSIF_CC_CINTS, 0, 30, 30, 30, 30, 0, "C <ia||jb>");
    global_dpd_->buf4_sort_axpy(&D, PSIF_CC_MISC, qrsp, 31, 31, "A(ai,bj)", -1.0);
    global_dpd_->buf4_close(&D);

    global_dpd_->buf4_init(&Amat, PSIF_CC_MISC, 0, 31, 31, 31, 31, 0, "A(ai,bj)");
    for (h = 0; h < nirreps; h++) {
        global_dpd_->buf4_mat_irrep_init(&Amat, h);
        global_dpd_->buf4_mat_irrep_rd(&Amat, h);

        for (row = 0; row < Amat.params->rowtot[h]; row++) {
            a = Amat.params->roworb[h][row][0];
            i = Amat.params->roworb[h][row][1];
            A = fab.params->rowidx[a];
            I = fij.params->rowidx[i];
            Asym = fab.params->psym[a];
            Isym = fij.params->psym[i];
            for (col = 0; col < Amat.params->coltot[h]; col++) {
                b = Amat.params->colorb[h][col][0];
                j = Amat.params->colorb[h][col][1];
                B = fab.params->colidx[b];
                J = fij.params->colidx[j];
                Bsym = fab.params->qsym[b];
                Jsym = fij.params->qsym[j];

                if ((I == J) && (Asym == Bsym)) Amat.matrix[h][row][col] += fab.matrix[Asym][A][B];
                if ((A == B) && (Isym == Jsym)) Amat.matrix[h][row][col] -= fij.matrix[Isym][I][J];
            }
        }

        global_dpd_->buf4_mat_irrep_wrt(&Amat, h);
        global_dpd_->buf4_mat_irrep_close(&Amat, h);
    }
    global_dpd_->buf4_close(&Amat);

    global_dpd_->buf4_init(&D, PSIF_CC_DINTS, 0, 22, 28, 22, 28, 0, "D <Ij|Ab>");
    global_dpd_->buf4_sort(&D, PSIF_CC_MISC, rpsq, 21, 31, "A(AI,bj)");
    global_dpd_->buf4_close(&D);
    global_dpd_->buf4_init(&Amat, PSIF_CC_MISC, 0, 21, 31, 21, 31, 0, "A(AI,bj)");
    global_dpd_->buf4_scm(&Amat, 2);
    global_dpd_->buf4_close(&Amat);

    global_dpd_->file2_mat_close(&fIJ);
    global_dpd_->file2_close(&fIJ);
    global_dpd_->file2_mat_close(&fij);
    global_dpd_->file2_close(&fij);
    global_dpd_->file2_mat_close(&fAB);
    global_dpd_->file2_close(&fAB);
    global_dpd_->file2_mat_close(&fab);
    global_dpd_->file2_close(&fab);
    global_dpd_->file2_mat_close(&fIA);
    global_dpd_->file2_close(&fIA);
    global_dpd_->file2_mat_close(&fia);
    global_dpd_->file2_close(&fia);
}

}  // namespace ccdensity
}  // namespace psi
